Portion of a bed



FIG. 1 is a front, perspective view of a portion of a bed showing our new design;

FIG. 2 is a rear, perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof; and,

FIG. 5 is a right-side view thereof, the left-side view being a mirror image.

The broken lines in the drawings, showing portions of a frame, supports for a mattress and holes, represent environmental subject matter and form no part of the claimed design. 

The ornamental design for a portion of a bed, as shown and described. 